Dore Marina Pereira, Farias Cássia, Hamacher Cláudia
AECOM Brazil, Praia de Botafogo, 440, 24° andar, Rio de Janeiro, RJ, 22250-040, Brazil.
Laboratório de Geoquímica Orgânica Marinha (LaGOM), Faculdade de Oceanografia, Universidade do Estado do Rio de Janeiro, Rua São Francisco Xavier, 524, 4° andar, Rio de Janeiro, RJ, 20550-900, Brazil.
Environ Monit Assess. 2017 Jan;189(1):44. doi: 10.1007/s10661-016-5757-6. Epub 2016 Dec 30.
The exploration and production of oil and gas reserves often result to drill cutting accumulations on the seafloor adjacent to drill locations. In this study, the detection of drilling influence on marine sediments was performed by meta-analytical comparison between data from pre- and post-drilling surveys undertaken in offshore Campos Basin, southeast of Brazil. Besides this overall appraisal on the geochemical variables, a multivariate assessment, considering only the post-drilling data, was performed. Among the variables, fines content, carbonates, total organic carbon, barium, chromium, copper, iron, manganese, nickel, lead, vanadium, zinc, and total petroleum hydrocarbons, only barium, copper, and hydrocarbons were related to drilling impacts. In relation to the point of discharge, relative elevated levels in the post-drilling campaigns were observed preferentially up to 500 m in the northeast and southwest directions, associated to the Brazil Current-predominant direction. Other distributed concentrations in the surroundings seem to indicate the dilution and dispersion of drilling waste promoted by meteoceanographic factors.
